1. Field of the Invention
The present invention relates to an information storage system, and in particular to an information storage system which stores information in a removable recording medium.
2. Description of the Related Art
Recently, a storage capacity of a removable recording medium which is used in information storage systems has become large. Thus, a large amount of information can be easily and quickly taken away by being recorded on the removable recording medium. For this reason, it is desired to improve security for information.
In a large-scale computer, security of the system can be maintained since the places in which the system is installed are relatively limited and only people having permission can enter those places. Additionally, a user is required to enter a password in order to access important data. Thus, it is not easy to access information in the case of the large-scale computer.
On the other hand, a personal computer, which has rapidly become wide spread, can be set in any place and anyone can easily access the system. With the recent spread of the personal computer, important data has become handled by the personal computer. Additionally, a storage capacity of a storage device of a removable recording medium type used in the personal computer has become large. For example, it is possible to record 640 MB of data in a single recording medium in the case of an optical disk apparatus such as a phase-change type optical disk (PD) apparatus and a magneto-optic disk apparatus, or a large capacity floppy disk apparatus.
FIG. 1 shows a system structure diagram of an example of a conventional information processing system. In the conventional system 50, a magneto-optic disk apparatus 52 is connected to a personal computer 51 via a SCSI interface. Information is recorded on and reproduced from a magneto-optic disk 53 which is mounted in the magneto-optic disk apparatus 52. In the conventional information processing system 50, no security is provided for the magneto-optic disk apparatus 52.
Therefore, if no security is provided for the personal computer 51, important data stored in a built-in hard disk of the personal computer 51 can be taken away by copying the data to the magneto-optic disk 53 by means of the magneto-optic disk apparatus 52. In this case, a large amount of data corresponding to an amount of data stored in several hundred floppy disks can be quickly and secretly taken away, because the magneto-optic disk 53 has a maximum capacity as large as 640 MB or even 1.3 GB.
Additionally, data which is stored in the magneto-optic disk 53 can be instantly copied or deleted. The conventional information processing system 50 has no protection against such a situation.
Accordingly, it is an object of the present invention to provide an information storage system which can be used by only those users who are previously permitted to access the system.
The above-mentioned object of the present invention can be achieved by an information storage system comprising:
a first information storage device for accessing a first removable recording medium;
a second information storage device for accessing a second removable recording medium; and
an access controller for controlling access to the first removable recording medium by the first information storage device based on a result of access to the second removable recording medium by the second information storage device prior to access to the first removable recording medium by the first information storage device.
According to the invention, since access to the first removable recording medium is permitted in accordance with the result of access to the second removable recording medium, a user who does not have the second removable recording medium cannot access the first removable recording medium. Hence, the security provided for information of the first information storage device can be improved.
In the above information storage system, the second information storage device may comprise a medium detector for detecting the second removable recording medium mounted in a predetermined position where the second removable recording medium can be accessed by the second information storage device.
In this case, the access controller may permit the first information storage device to access the first removable recording medium when the medium detector detects the second removable recording medium mounted in the predetermined position.
According to the invention, since access to the first removable recording medium is permitted when the medium detector detects the second removable recording medium mounted in the second information storage device, a user who does not have the second removable recording medium cannot access the first removable recording medium. Hence, the security provided for information of the first information storage device can be improved.
The access controller may turn on power supply to the first information storage device when the medium detector detects the second removable recording medium mounted in the predetermined position.
According to the invention, when the second removable recording medium is not mounted in the second information storage device, the first information storage device cannot access the first removable recording medium since the first information storage device is not supplied with power. Hence, a user who does not have the second removable recording medium cannot access the first removable recording medium, and as a result, the security provided for information of the first information storage device can be improved.
In the above-mentioned information storage system, the second information storage device may comprise a information reader for reading out information recorded on the second removable recording medium.
In this case, the second removable recording medium may be provided with access permission information recorded thereon; and
the access controller may control access to the first removable recording medium by the first information storage device based on the access permission information read by the information reader.
According to the invention, since access to the first removable recording medium is controlled in accordance with the access permission information recorded on the second removable recording medium, the security provided for information of the first information storage device can be improved.
The access permission information may comprise write permission information for permitting the first information storage device to write information to the first removable recording medium.
In this case, the access controller may permit the first information storage device to write information to the first removable recording medium when the write permission information is valid.
According to the invention, write access to the first removable recording medium by the first information storage device can be restricted based on the write permission information. Hence, it is possible to prevent information from being taken away after having been recorded on the first removable recording medium, and thus, the security provided for information of the first information storage device can be further improved.
The access permission information may comprise read permission information for permitting the first information storage device to read information from the first removable recording medium.
In this case, the access controller may permit the first information storage device to read information from the first removable recording medium when the read permission information is valid.
According to the invention, read access to the first removable recording medium by the first information storage device can be restricted based on the read permission information. Hence, it is possible to prevent information from being easily read out from the first removable recording medium, and thus, the security provided for information of the first information storage device can be improved.
The access permission information may comprise a control program for controlling the access controller; and
the access controller may control access to the first removable recording medium by the first information storage device in accordance with the control program.
According to the invention, since the first removable recording medium cannot be accessed without the second removable recording medium being provided with the control program recorded thereon, the security provided for information of the first information storage device can be improved.
The information storage system may further comprise a control program setting part for validating or invalidating the control program.
In this case, the access controller may control access to the first removable recording medium by the first information storage device in accordance with the control program when the control program is validated by the control program setting part; and
the access controller may control access to the first removable recording medium by the first information storage device irrespective of the control program when the control program is invalidated by the control program setting part.
According to the invention, since the control program can be easily validated or invalidated by the control program setting part, it is possible to change an extent of the security in accordance with various situations.
The above-mentioned object can also be achieved by an information storage system comprising:
a first information storage device for accessing a first removable recording medium;
a second information storage device for accessing a second removable recording medium to read out first access permission information recorded on the second removable recording medium;
an access permission information storage part for storing second access permission information; and
an access controller for permitting the first information storage device to access the first removable recording medium when the first access permission information read out by the second information storage device and the second access permission information stored in the access permission information storage part satisfy a predetermined condition.
According to the present invention, the access to the first removable recording medium by the first information storage device can be controlled in accordance with the first access permission information recorded on the second removable recording medium and the second access permission information stored in the access permission information storage part. Thus, more sophisticated access control can be achieved so that the security provided for information of the first information storage device is further improved.
In the above information storage system, the access controller may permit the first information storage device to access the first removable recording medium when the first access permission information corresponds to the second access permission information.
According to the present invention, the first removable recording medium can be accessed by only those who have the second removable recording medium containing the first access permission information corresponding to the second access permission information stored in the access permission information storage part. Thus, the security provided for information of the first information storage device can be improved.
The first access permission information may comprise write permission information for permitting the first information storage device to write information to the first removable recording medium.
According to the invention, since write access to the first removable recording medium can be restricted based on the write permission information, it is possible to prevent information from being taken away after having been recorded on the first removable recording medium. Thus, the security provided for information of the first information storage device can be further improved.
The first access permission information may comprise read permission information for permitting the first information storage device to read information from the first removable recording medium.
According to the invention, since read access to the first removable recording medium can be restricted based on the read permission information, it is possible to prevent information from being easily read out from the first removable recording medium. Thus, the security provided for information of the first information storage device can be further improved.
The access controller may permit the first information storage device to write information to the first removable recording medium when the write permission information is valid.
According to the invention, security against write access to the first removable recording medium can be easily changed based on the write permission information.
The access controller may permit the first information storage device to read information from the first removable recording medium when the read permission information is valid.
According to the invention, security against read access to the first removable recording medium can be easily changed based on the read permission information.
The first access permission information may comprise a control program for controlling the access controller; and
the access controller may control access to the first removable recording medium by the first information storage device in accordance with the control program.
According to the invention, since the first removable recording medium cannot be accessed without the second removable recording medium provided with the control program recorded thereon, the security provided for information of the first information storage device can be improved.
The information storage system may further comprise a control program setting part for validating or invalidating the control program.
In this case, the access controller controls access to the first removable recording medium by the first information storage device in accordance with the control program when the control program is validated by the control program setting part; and
the access controller controls access to the first removable recording medium by the first information storage device irrespective of the control program when the control program is invalidated by the control program setting part.
According to the invention, the access controller controls access to the first removable recording medium based on the validity of the control program. Thus, it is possible to change an extent of the security against access to the first removable recording medium in accordance with various situations.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.